SJ Weir Ltd v Bijok - [2011] SASCFC 165

SUPREME COURT OF SOUTH AUSTRALIA
(Full Court)
SJ WEIR LTD v BIJOK & ANOR
[2011] SASCFC 165
Judgment of The Full Court
(The Honourable Justice Gray, The Honourable Justice Sulan and The Honourable Justice Blue)
23 December 2011
TORTS - NEGLIGENCE - GENERAL MATTERS
TORTS - NUISANCE - WHAT CONSTITUTES - PRIVATE NUISANCE
Appeal against award of damages to plaintiffs in negligence and nuisance.
Appellant undertook building work on land adjoining respondents' property - excavation work caused subsidence of adjoining land and damage to respondents' carport, driveway and house - retaining wall constructed by appellant found to be inadequate.
Whether the trial Judge was entitled to conclude from the evidence of Mr Vreugdenburg that the appellant proceeded to erect a retaining structure in contravention of the engineer's advice - whether the circumstances attracted the principle of res ipsa loquitur - whether liability in nuisance arose.
Held: Appeal dismissed.
Gray and Sulan JJ: Appellant breached duty of care by failing to provide adequate retention and by acting contrary to engineering advice - circumstances attracted the principle of res ipsa loquitur - breach was a material cause of the subsiding of the soil causing damage to property - negligence proven - further finding of liability in private nuisance open to trial Judge.
Blue J: As to nuisance, the trial Judge correctly found the nuisance caused the loss - as to negligence, the trial Judge correctly found that the appellant departed from the engineer's design - the doctrine of res ipsa loquitur applied and the appellant's negligence caused the loss - and s 72 of the Development Act did not apply becuase the appellant failed to prove negligence by the engineer or causation of loss.
Development Act 1993 (SA) s 72, referred to.
Bijok & Anor v S J Weir Pty Ltd [2011] SADC 20; Donoghue v Stevenson [1932] AC 562; Schellenberg v Tunnel Holdings (2000) 200 CLR 121; Jemena Gas Networks (NSW) Ltd v Mine Subsidence Board (2011) 85 ALJR 666; Watts v Rake (1960) 108 CLR 158, applied.
Jones v Dunkel (1959) 101 CLR 298; Piening v Wanless (1968) 117 CLR 498; Anchor Products Ltd v Hedges (1966) 115 CLR 493; Mummery v Irvings Pty Ltd (1956) 96 CLR 99; Bonomi v Backhouse (1859) EB & E 646; Backhouse v Bonomi (1861) 9 HL Cas 503; Dalton v Henry Angus & Co (1881) 6 App Cas 740; Brown v Robins (1859) 4 H & N 186 [157 ER 809]; Stroyan v Knowles (1861) 6 H & N 454 [158 ER 186]; Pantalone v Alaouie (1989) 18 NSWLR 119; Darley Main Colliery Co v Mitchell (1886) 11 App Cas 127; Hargrave v Goldman (1963) 110 CLR 40; Walker v Adelaide City Corporation (2004) 88 SASR 225; Kebewar Pty Ltd v Harkin (1987) 9 NSWLR 738; Morgan v Lake Macquarie City Council [1993] NSWCA 184 (Unreported, NSW Court of Appeal, 2 September 1993); Savini v Australian Terrazzo and Concrete Co Pty Ltd [1959] VLR 811; Middleton v Melbourne Tramway & Omnibus Co Ltd (1913) 16 CLR 572, considered.

SJ WEIR LTD v BIJOK & ANOR
[2011] SASCFC 165
Full Court: Gray, Sulan and Blue JJ
GRAY and SULAN JJ

This is an appeal against a judgment awarding damages to the plaintiffs in negligence and nuisance following a trial in the District Court.
The defendant and appellant, SJ Weir Pty Ltd, a builder, undertook building work on land at Glenelg. The development was called “the Moorings”. John and Maria Bijok were the owners of a house property on land adjoining the property the subject of the proposed development. They claimed that damage was caused to their property as a result of excavations undertaken by SJ Weir on the neighbouring property. The Judge found in their favour in both negligence and nuisance.
Before coming to discuss the issues arising on the appeal, it is convenient to set out the background facts. Mr and Mrs Bijoks’ property is situated on King Street, Glenelg. That street runs east-west between the Patawalonga and North Esplanade. There are other house properties in the area. Before being built on, the area consisted mainly of sand dunes.
The Bijoks built their home in 1967. At the time of building, the Bijoks were aware that the sandy soil on which their house stood could be unstable. With this in mind, their land was retained by a wall on all sides save for the frontage to King Street. The house was situated in the middle of the block.
The eastern boundary of the Bijok land adjoined the land on which SJ Weir was to undertake building work. On that eastern boundary of the Bijoks’ property a concrete driveway extended south from King Street to a brick carport, followed by a further section of driveway and a brick garage. The driveway, carport and garage were positioned at a slightly higher level than the vacant land immediately to the east.
The developers of the adjoining land had initially been joined as defendants but those proceedings were discontinued. The remaining defendants were the builder, SJ Weir, and its director, Robert Weir. Meinhardt PT Design Pty Ltd provided engineering advice in regard to the work to be undertaken by SJ Weir. Mr Andre Vreugdenburg, a director of the company, Meinhardt, was involved. Meinhardt were not a party to the proceedings.
The Judge found that SJ Weir tendered for the contract partly on the basis of the plans prepared by Meinhardt. The initial tender price was in the order of $12 million but after negotiations between the builder, architect and developer, the contract price was agreed at a lesser figure, nearer to $10 million. It appears that design changes were made in an effort to save money.
The plans for the Moorings included a basement carport with an access ramp adjacent to the Bijoks’ eastern boundary. The construction of the ramp required extensive excavation along the common boundary which in turn required a retaining structure to prevent movement of soil under the Bijoks’ property and to prevent possible damage to their buildings and driveway.
SJ Weir constructed a retaining wall which proved to be inadequate. Soil escaped from the Bijoks’ property causing subsidence especially under the carport which in turn led to further damage. The issue at trial was whether SJ Weir was liable in negligence and nuisance for the resultant damage.
The Judge in his reasons for judgment outlined the Bijoks’ case – that SJ Weir, to save money, built a retaining wall that was not approved by the engineer and that the wall was inadequate, leading to the collapse of the soil under their house. The Judge outlined the builder’s case – that the fault lay with the engineer through bad design and that the builder met its duty of care by following the engineer’s advice. The builder was not at fault.
As noted above, Meinhardt was not joined as a party in the proceedings. However, when giving evidence Mr Vreugdenburg denied that Meinhardt had approved the use of the retaining wall which the builder had erected along the carport section of the boundary.
It is convenient to draw from the Judge’s reasons the undisputed history concerning the design to be adopted:[1]
[1] Bijok & Anor v S J Weir Pty Ltd [2011] SADC 20, [12]-[13].
From the earliest stages of design, it was clear to all those involved that there would have to be significant retaining structures on the Bijok boundary and that the soil type - loose sand - presented special difficulties. In its geotechnical report of 22 October 2002, Coffey Geoscience Pty Ltd described the soil at various levels and reported the need for temporary support during excavation saying:
‘Excavations of depths up to 1.5 metres in dune sand will not stand vertically even for a short period. As a result temporary support would need to be provided …’
Later in the report, Coffey’s said:
‘Careful consideration will need to be taken of allowable lateral movements of the retaining structure along [the Bijok boundary], where existing buildings abut the site. These existing buildings could be adversely affected should lateral movements become excessive. In addition, the footings of existing buildings may require underpinning depending upon their type, founding depth and location relative to the excavation …
The adoption of driven sheet pile walls is not recommended due to the potential for damage of adjacent structures through the driving vibrations.’
As a consequence, Meinhardt provided SJ Weir with engineering designs for the work including a design for the proposed retaining structure. A note in respect of the carport retaining wall specified:
Mass concrete underpins to be installed in segments of 600 mm. Sequence of excavation and pouring of underpins to be in accordance with Day Number as noted above.
The Judge addressed this issue as follows:[2]
In other words, Meinhardt proposed, by way of underpinning for the carport section, a series of concrete piers. They were not all to be poured at the same time but over a number of days so that piers poured earlier could support the gaps left by areas excavated for piers to be poured later. It is a slow method of construction. Further, Mr Weir always perceived problems with such mass concrete underpinning: he could not see how it could work in that soil type. So concerned was he that, before signing the contract, he had already made enquiries about using an alternative method.
[2] Bijok & Anor v S J Weir Pty Ltd [2011] SADC 20, [16].
In May 2003, the Bijoks became alarmed. Demolition work was causing their property to shake. A meeting took place on site on 4 June 2003 between the Bijoks, a consulting engineer advising the Bijoks, Mr Weir and Mr Vreugdenburg.
SJ Weir had sought and obtained a proposed alternative to the mass concrete piers that had been the subject of the original Meinhardt design. This alternative design, which involved less expense, had been discussed with Mr Vreugdenburg who expressed reservations in a facsimile to Mr Weir on 5 June 2003 in the following terms:[3]
I expressed to him [Harry] the cautious nature required in the approach in that the type of ground is extremely unpredictable, speed is of the essence and in the event of a collapse he may have to revert to conventional methods.
Mr Vreugdenburg did not, however, preclude a trial of the alternative procedure that had been proposed but he requested that he be informed about the results of such a trial. No trial eventuated.
[3] Bijok & Anor v S J Weir Pty Ltd [2011] SADC 20, [20].
On 11 June 2003, all work on site stopped for reasons unrelated to issues with the Bijoks’ property. At this time, Mr Weir sought alternative designs for the temporary retaining walls to be erected along the Bijok boundary. It is apparent that Mr Weir was concerned about time and cost. Mr Vreugdenburg provided a further design for the driveway section only. The Judge described this design as follows:[4]
Mr Vreugdenburg proposed in his design that soil under the Bijoks' boundary be retained by installing a series of metal I-beams which would support, behind them, steel sheets so that the whole structure formed a wall intended to prevent any movement on the Bijok site.
The Judge noted in his reasons that there was no dispute that the further design prepared on this occasion was for the driveway section only and not for the area of the carport.
[4] Bijok & Anor v S J Weir Pty Ltd [2011] SADC 20, [23].
At a site meeting on 26 June 2003, some discussions ensued between Mr Weir and Mr Vreugdenburg about the use of the alternative design for the driveway being used in the area of the carport. Mr Vreugdenburg said that he was prepared to consider such a system but with a proviso. A sketch was made and calculation prepared by a Meinhardt engineer and submitted to the builder. This sketch and the calculations required what was described by the Judge as further propping.
Work proceeded along the Bijok eastern boundary. SJ Weir used the approved alternative design for the driveway when constructing a retention wall for the northern driveway area. SJ Weir then continued to use that design along the carport area. In other words, SJ Weir used the design that Mr Vreugdenburg had advised was not suitable for the carport area and SJ Weir made no attempt to use the initial design of mass concrete piers. SJ Weir proceeded to construct a retaining wall in accordance with a design that it had been advised by Meinhardt would not be suitable.
On 2 August 2003, a section of the soil beneath the carport on the Bijoks’ property subsided causing damage to the Bijoks’ carport, driveway and house. Given the warnings and the use of an unsuitable design, this was unsurprising. The Judge noted that “there is no dispute that the subsidence caused the damage the subject of the Bijok claim”.
In the course of the trial, SJ Weir and Meinhardt were “at odds” as to the recommended design for the system of temporary retention. Mr Vreugdenburg’s position was that Meinhardt did not approve the alternative design for the driveway retention as being suitable for carport retention. It was the Meinhardt position that the builder did not comply with the engineer’s design when building a retaining wall in the area of the carport. SJ Weir’s position was that Meinhardt had approved the very design that was utilised.
The Judge accepted Mr Vreugdenburg’s evidence and concluded that SJ Weir proceeded to erect a retaining structure “in contravention of the engineer’s design”. In particular, the Judge observed:[5]
I shall decide the case on the evidence before me. The clear effect of that evidence is that, for the carport section Mr Vreugdenburg had designed a system which included propping. The relevant section of the boundary was not propped before 2 August. It may well be that Daniel Lee, on a visit to the site, saw that the work was proceeding without the props in place. I can take that issue no further. I accept Mr Vreugdenburg’s evidence and I find that, in contravention of the engineer’s design, the builder proceeded with an unpropped retaining structure. After the subsidence props were installed and the excavation proceeded without further subsidence. I infer from the lack of further subsidence that the propping design was adequate. Therefore the builder is solely responsible for the subsidence under the Bijok’s land.
[5] Bijok & Anor v S J Weir Pty Ltd [2011] SADC 20, [34].
On appeal a challenge was made to the Judge’s acceptance of Mr Vreugdenburg’s evidence. This challenge, however, did little more than repeat the arguments put to the Judge at trial. The Judge’s acceptance of Mr Vreugdenburg’s evidence was plainly open to him. Nothing was advanced on the appeal to suggest that the Judge failed to have regard to any material evidence or made any inappropriate use of other evidence tendered in the trial. Mr Vreugdenburg’s account received some support from written records. We reject the challenge made to the Judge’s acceptance of Mr Vreugdenburg’s evidence.
In our view, SJ Weir owed the Bijoks a duty of care. In every sense, they were neighbours.[6] SJ Weir was aware of the risks associated with excavation and in particular the risks to the Bijoks’ property. SJ Weir were in control of the excavation process and the Bijoks were vulnerable. The report of Coffey and Partners made available to SJ Weir highlighted the dangers of the work to be undertaken. This was also emphasised by Mr Vreugdenburg. We consider that the duty of care owed by SJ Weir required reasonable steps to guard against the collapse of soil underlying the Bijoks’ property, in light of knowledge of the very real risk of that soil collapsing. It was reasonably foreseeable that without an adequate retaining wall the soil would, in all probability, collapse with resultant damage.
[6] Donoghue v Stevenson [1932] AC 562.
SJ Weir failed to provide adequate retention. It did not follow the engineer’s advice. It acted contrary to the advice. It erected a retaining wall in the area of the carport that they had been advised was unsuitable. This was a breach of the duty owed to take care. The wall was inadequate and caused soil to escape from the Bijok property. As noted earlier, this was unsurprising. We see no reason why liability in negligence should not follow.
The circumstances attract the principle of res ipsa loquitur. We refer to this principle in accordance with the observations of Gleeson CJ and McHugh J in Schellenberg v Tunnel Holdings:[7]
What flows from these statements of principle is that, while res ipsa loquitur may ameliorate the difficulties that arise from a lack of evidence as to the specific cause of an accident, the inference to which it gives rise is merely a conclusion that is derived by the trier of fact from all the circumstances of the occurrence. When it applies, the trier of fact may conclude that the defendant has been negligent although the plaintiff has not particularised a specific claim in negligence or adduced evidence of the cause of the accident. But it does nothing more. For example, it does not reverse the onus of proof or displace the principle in Jones v Dunkel.[8]
Piening v Wanless[9] and Anchor Products Ltd v Hedges[10] as well as other cases in this Court make it clear that a plaintiff may rely on res ipsa loquitur even though he or she has also pleaded particular acts or omissions of negligence on the part of the defendant provided that the tribunal of fact concludes that: (1) there is an "absence of explanation" of the occurrence that caused the injury; (2) the occurrence was of such a kind that it does not ordinarily occur without negligence; and (3) the instrument or agency that caused the injury was under the control of the defendant.
[7]    Schellenberg v Tunnel HoldingsPty Ltd (2000) 200 CLR 121 at [24]-[25].
[8]    Jones v Dunkel (1959) 101 CLR 298.
[9]    Piening v Wanless (1968) 117 CLR 498.
[10] Anchor Products Ltd v Hedges (1966) 115 CLR 493.
It was obvious that excavation of sandy soil without adequate retention would lead to subsidence of nearby sandy soil. Any child digging a moat for a sandcastle on the beach would have encountered this inevitable occurrence. Alternatively, if this was not to be treated as an occurrence that would not ordinarily occur without negligence, the circumstances readily allow the inference to be drawn that SJ Weir had acted in breach of its duty of care and is liable for the resultant damage caused by that breach.[11] In Schellenberg, Gleeson CJ and McHugh J addressed this issue as follows:[12]
As soon as the immediate cause of the accident is established, the focus of the case changes. The question then becomes whether that cause was the product of negligence on the part of the defendant. That is the effect of Mummery v Irvings Pty Ltd[13] and Piening v Wanless.[14]
That the principle of res ipsa loquitur ceases to operate once the cause of the occurrence is identified does not mean that the plaintiff cannot rely on inferential reasoning to prove negligence. Thus, in a case like the present, with sufficient evidence, it might be inferred that it was lack of reasonable maintenance that caused the hose to become detached. There was nothing to stop the plaintiff in this case, for example, from relying on res ipsa loquitur and also adducing evidence that the defendant had no system for inspecting the couplings. If he had done so, he would have been entitled to argue that the lack of such a system was negligent and that, if the hose had separated from the jamec coupling, it was proper to infer a causal connection between the lack of an inspection system and the detachment of the hose.
As noted above, the Judge recorded that it was not in issue that the subsidence caused the damage to the Bijok property.
[11] Schellenberg v Tunnel Holdings Pty Limited (2000) 200 CLR 121.
[12] Schellenberg v Tunnel Holdings Pty Limited (2000) 200 CLR 121 at [36]-[37].
[13] Mummery v Irvings Pty Ltd (1956) 96 CLR 99 at 117.
[14] Piening v Wanless (1968) 117 CLR 498.

On appeal, SJ Weir contended that the case at trial was not presented on this basis. Our review of the pleadings and the evidence suggest the contrary. The Judge, as earlier discussed, summarised the Bijoks’ case in the broadest terms and in such a manner as to encompass the above analysis. We reject the suggestion that the Bijoks were not entitled to rely on the principle of res ipsa loquitur or alternatively to draw the inferences referred to above.
It was further contended on appeal that the alternative methodology of extended propping would not have been adequate in any event. In other words, the methodology that was allegedly approved by Meinhardt with respect to the carport would not have been sufficient in any event. When addressing this submission, it is important to recall that SJ Weir did not adopt the specified method of construction of mass concrete piers. It is evident that SJ Weir sought to adopt less expensive methods of retention. Even if one were to accept that Meinhardt had approved the extended propping method, SJ Weir did not adopt this method. Rather, SJ Weir continued the method that had been used to support the driveway, ignoring the advice of Meinhardt that this would not be adequate. In other words, SJ Weir adopted a method specifically disapproved of by Meinhardt.
There is a further difficulty. By the time extensive propping was attempted the status quo had changed. Subsidence had occurred. The fact that extensive propping may not have been effective following the early collapse, does not establish that it would not have been satisfactory had that method been used from the outset.
In these circumstances, we conclude that the breach of duty by SJ Weir was a material cause of the subsiding of the soil which in turn was the cause of the damage to the Bijoks’ property.
On the findings of the trial Judge, there was no basis on which to conclude that Meinhardt had been negligent. Equally, on the view we have taken, there is no basis for concluding that Meinhardt was negligent. In these circumstances, section 72 of the Development Act 1993 (SA) could have no application. In this respect we agree with the reasons of Blue J.
For these reasons, we would dismiss the appeal insofar as it seeks to challenge the finding of negligence on the part of SJ Weir.
An owner of land has a right to the support of that land in its natural state from the adjacent and sub-adjacent land of neighbouring owners. This long established principle was recently endorsed and applied by the High Court in Jemena Gas Networks (NSW) Ltd v Mine Subsidence Board where the Court observed:[15]
If the Act had not been enacted, and if no provision corresponding to s 14 existed, at common law the proprietor of a colliery holding, although not liable for a mere withdrawal of support, and not liable merely for subsidence caused by that withdrawal of support, would be liable in nuisance for a withdrawal of support creating subsidence which caused actual damage.[16] This is because the owner of land has a right to the support of that land in its natural state from the adjacent and subjacent land of neighbouring owners (including lessees). The right is a natural incident of the ownership. There is no natural right of support for structures (as distinct from the natural right of support for land in its natural state) but damages for injury to a structure flowing from subsidence caused by a withdrawal of support (as distinct from the additional weight of structures on the land) are recoverable.[17] … But each successive subsidence causing damage creates a fresh cause of action, even though there has been no new excavation.[18]
[15] Jemena Gas Networks (NSW) Ltd v Mine Subsidence Board (2011) 85 ALJR 666.
[16] Bonomi v Backhouse (1859) EB & E 646 at 626 [120 ER 652]; Backhouse v Bonomi (1861) 9 HL Cas 503; Dalton v Henry Angus & Co (1881) 6 App Cas 740 at 808.
[17] Brown v Robins (1859) 4 H & N 186 [157 ER 809]; Stroyan v Knowles (1861) 6 H & N 454 [158 ER 186]; Pantalone v Alaouie (1989) 18 NSWLR 119 at 129.
[18] Darley Main Colliery Co v Mitchell (1886) 11 App Cas 127.
A private nuisance is a substantial and unreasonable interference with the private right to the use and enjoyment of land. To establish a cause of action in nuisance the plaintiff must demonstrate the holding of title to sue in respect of the particular nuisance and that the defendant has interfered with a property right of the plaintiff. Interference must be both substantial and unreasonable.[19]
[19] The propositions have been drawn from Halsbury’s Laws of Australia which in turn have been drawn on long established case law.
As Windeyer J observed in Hargrave v Goldman:[20]
…A nuisance has been defined as an "unlawful interference with a person's use or enjoyment of land, or of some right over, or in connexion with it". This compendious description from Winfield on Tort 6th ed. (1954) p. 536 states the essence of nuisance as a tort. But some particularity is required to give content to the phrase "unlawful interference". Generally speaking the term "nuisance" denotes a state of affairs that is either continuous or recurrent. It is, therefore, somewhat misleading to use the word "nuisance" of a situation from which harm may occur if care be not exercised, but from which no actual harm is currently occurring. A thing that dangerously overhangs a highway, and which may fall at any moment, is however commonly called a nuisance. It currently and continuously interferes with the safe enjoyment of a public right of way and is thus a public nuisance. But in the present case what the appellants relied upon was the law of private nuisance. And a fire that is presently harmless is not a nuisance, although it may be fraught with danger and arouse apprehensions of harm. It is not that the law ignores prospective nuisances or threatening dangers. It does not, for their existence may be a ground for an injunction: Attorney-General v. Corporation of Manchester. And there can be no objection to speaking of a "potential nuisance", as was done in this case, provided that it be remembered that the invasion of the common law rights of an owner or occupier of land does not occur until he suffers harm: cf. Torette House Pty. Ltd. v. Berkman, per Dixon J. The matter may seem to be one of classification and terminology, rather than of substance; but the boundaries of the law of nuisance are indefinite enough without allowing the word to beg the question. It is nearly a hundred years since Erle C.J. said of nuisance, in a judgment which, because of his resignation, was never delivered: "This cause of action is immersed in undefined uncertainty ... The maxim, "sic utere tuo ut alienum non laedas", is no help to decision, as it cannot be applied till the decision is made; and the use of the word "nuisance" in the discussion prolongs the dispute, because it means both annoyance that is actionable, and also that which is not actionable; and where the question is whether an annoyance is actionable, the word "nuisance" introduces an equivocation which is fatal to any hope of a clear settlement.": Brand v. Hammersmith and City Railway Co.
[Footnotes omitted.]
[20] Hargrave v Goldman (1963) 110 CLR 40, 59.
It was accepted on appeal that the evidence had established that a nuisance had occurred through the undermining of the Bijoks’ property. The contention on the appeal was that no liability in nuisance arose because the additional weight of the Bijoks’ dwelling was a cause of the subsidence.
Attention was drawn to the evidence of an expert engineer, Mr Trevor Kokkinakis. Blue J has set out extracts from the cross-examination and re-examination of this witness. In cross-examination, Mr Kokkinakis did not accept that the likelihood of subsidence had increased because of the weight of the building on the property, but added that the weight of the building may have led to a greater degree of subsidence. In re-examination, however, Mr Kokkinakis agreed that if the building had not been on the land, the subsidence would have occurred.
We reject the submission that this evidence allowed the conclusion that the building was the cause or a cause of the subsidence. The evidence does not justify such a conclusion. To the contrary, the evidence given in re-examination was that the subsidence would have occurred regardless of the presence of the building. The Judge accepted the evidence in re-examination and observed:
An owner of land has a right to support offered to his land in its natural state by adjoining land. But that right does not extend to support for a structure - such as the Bijoks’ carport - on the land unless it is shown that the weight of the structure did not contribute to the nuisance.[21] Mr Kokkinakis’s evidence is that the weight of the carport did not cause the subsidence although it extended its effects. To put it another way, had the carport not been there, the subsidence still would have occurred. In those circumstances, I find that the weight of the carport did not cause the subsidence and the builder is, therefore, liable in nuisance.
In our view, these findings and conclusions were open to the Judge. No adequate basis has been advanced to justify this Court reaching a contrary view.
[21] Walker v Adelaide City Corporation (2004) 88 SASR 225 at [256].
We agree with the further observations of Blue J in regard to the onus of proof. In the circumstances, SJ Weir bore the onus of establishing that the weight of the building was relevantly the cause. SJ Weir did not discharge that onus.
For these reasons, we would dismiss the appeal.
BLUE J: The respondent house owners Mr and Mrs Bijok (“the Bijoks”) sued the appellant builder SJ Weir Pty Ltd (“SJ Weir”) in the District Court in nuisance and negligence for damage to their carport, driveway and retaining wall which resulted from excavations by SJ Weir on land next door.
The trial Judge found SJ Weir liable in both nuisance and negligence for damages in the sum $141,710. SJ Weir appeals to this Court from that judgment.
Background facts
The Bijoks own a block of land at Glenelg. It comprises windblown sand dunes. Structures erected on it include a carport on the eastern side of the house, a driveway running along the eastern boundary to the carport, and a retaining wall along the eastern boundary.
In 2002, developers acquired the land to the east of the Bijok block to construct an apartment building. They engaged Meinhardt PT Design Pty Ltd (“Meinhardt”) as engineers and SJ Weir as the builder.
The developers intended to construct a basement carport, with an access ramp leading down to the carport along part of their western boundary. They intended to construct mass concrete underpins beneath the Bijoks’ carport and to construct a temporary retaining wall adjacent to the Bijoks’ driveway against which they would ultimately construct a permanent masonry retaining wall.
In June 2003, SJ Weir commenced excavation. At that point, Meinhardt had prepared drawings for the concrete underpins to the Bijok carport. SJ Weir had proposed to Meinhardt an alternative method of installing the underpins (by machine-bored excavations), but this specific method and the question of underpinning generally was in a state of uncertainty.
On 11 June, the local council issued an enforcement notice requiring all work to cease. SJ Weir requested that Meinhardt prepare a design for the temporary retaining wall along the western boundary to adjoin the Bijoks’ driveway.
On 12-13 June, Meinhardt prepared drawings and computations involving the installation of 11 steel I-beam columns (“steel columns”) spaced 1150mm apart (centre to centre) in the ground along the western boundary of the development site adjoining the Bijok driveway, with metal sheeting installed immediately behind the steel columns to retain the soil (ie sand) within the Bijoks’ boundary. On 13 June, Meinhardt sent the design drawings and computations to SJ Weir.
On 13 June, SJ Weir sent a letter to the Bijoks enclosing the Meinhardt design drawings and computations, referring to the original intention to underpin their footing on their eastern boundary and proposing an alternative approach of piecemeal shoring and retention per the Meinhardt drawing. It was common ground at trial and on appeal that, as at 13 June, the only design for a temporary retaining wall prepared by Meinhardt was for the area adjacent to the driveway and not the area adjacent to the carport. However, the letter proceeded on the basis of SJ Weir simply extending that design to the area adjacent to the carport as well.
On 23 June, a site meeting took place. The topic of retention on the western boundary of the development site was discussed. The minutes record “Meinhardt to reconsider the southern and western temporary retaining structure, allowing to temporary prop the columns” (sic). The principal Meinhardt engineer, Mr Vreugdenburg, gave evidence that:
1.there was a consensus reached by the time of the meeting that there would be difficulties in achieving the proposed underpinning to the Bijoks’ carport;
2.an alternative was suggested at the meeting, namely to extend the steel column/metal decking temporary retaining wall mechanism to the boundary adjacent to the carport as well;
3.Mr Vreugdenburg said at the meeting that, if this were done, it would be necessary to “prop the columns”, ie to attach diagonal steel props to the top of the steel columns running down to the excavated ground level well within the boundary of the development site.
On 3 July, Meinhardt prepared computerised computations and a design drawing for a temporary retaining wall adjacent to the Bijoks’ carport. The drawing and computations were entitled “Underpinning Alternatives”. The design involved the use of propped steel columns spaced 1500mm apart and metal decking. Later in July, Meinhardt prepared a handwritten diagram and computations, also entitled “Underpinning Alternatives”, referring to the meeting of 23 June. These also showed the same design. They showed the lateral force of the Bijoks’ soil (sand) at 15.6 kiloNewtons. They showed additional force (surcharge) of 2.2 kiloNewtons and 5.4 kiloNewtons described as “wall”. This gave a total force of 23.2 kiloNewtons. The case was conducted by SJ Weir on the basis that the force of the soil (sand) was 17.8 kiloNewtons and the force of the building (carport) was 5.4 kiloNewtons.
Between 7 and 14 July, Meinhardt submitted these design details to SJ Weir.
By 2 August, SJ Weir had installed steel columns at 1150mm spacings without propping along the western boundary and was in the process of installing the metal sheeting behind the columns simultaneously with excavation of sand. The metal decking was installed progressively as the excavation proceeded deeper.
On 2 August at about 3pm, an incident occurred in which sand beneath the Bijoks’ carport escaped into the development site. Mr Vreugdenburg, Mr Weir and Mr Bay (an engineer who had been engaged by the Bijoks) were informed and travelled quickly to site. However, before they arrived, SJ Weir’s workers had pushed sand up against the boundary. Accordingly, the engineers and Mr Weir did not see the nature, precise location or mechanism of the escape of sand.
As a result of the escape, the ground level of the Bijoks’ land in the vicinity of the carport fell. Mr Bay measured the differential between 31 May and 31 August 2003 at amounts ranging from 28mm at one end to 18mm at the other end of the carport. He also measured a fall of 4mm at the Bijok driveway towards the road and 13mm at the Bijok driveway further towards the carport. As a result of the fall in ground level, substantial cracks appeared in the Bijok carport, driveway and retaining wall.
Reasoning of the trial Judge
Nuisance
The trial Judge found that SJ Weir was responsible for any nuisance both as occupier of the development site and creator of the nuisance as the excavator. This conclusion is not challenged by SJ Weir on appeal.
The trial Judge held that the Bijoks, as owners of the adjoining land, had a right to support for their land in its natural state from the adjoining land. This conclusion is not challenged by SJ Weir on appeal.
The trial Judge held that this right did not extend to support for the Bijoks’ carport, driveway or other man made structures on the land.[22] This conclusion is not challenged by the Bijoks on appeal.
[22] Because he held that such a right can only be created under the Real Property Act 1886 (SA) by a registered easement.
The trial Judge referred to evidence by an expert engineer called by the Bijoks at trial, Mr Kokkinakis, that, had the carport not been there, the subsidence still would have occurred, although the carport extended its effects. In those circumstances, the trial Judge concluded that the weight of the carport did not cause the subsidence and SJ Weir was liable in nuisance for the whole of the damage. This conclusion is challenged by SJ Weir on appeal (“ground 1”).
Negligence
The plaintiffs in their statement of claim relevantly pleaded that the works by SJ Weir (including excavation and installation of the temporary retaining wall) caused damage to their land and structures on 2 August 2003;[23] the works caused cracking and movement in their carport, driveway and retaining wall;[24] SJ Weir knew that the underlying sub-surface material contained loose soils which when excavated would not stand vertically without adequate support and that the works would cause damage if measures were not taken to maintain support to the Bijok land;[25] that SJ Weir beached its duty of care by failing to take reasonable care to ensure that the works did not cause the damage that was caused;[26] and that, inter alia,[27] putting the steel columns and metal decking in place caused disturbance to the soil.[28]
[23] Statement of claim [13], [13.8].
[24] Statement of claim [15] – [17].
[25] Statement of claim [28]
[26] Statement of claim [29].
[27] They also pleaded that the method of constructing the retaining wall was inappropriate, the metal decking lacked rigidity and props were not installed.
[28] Statement of claim [26.4.3].
In turn, SJ Weir admitted that it owed a duty of care, denied that it breached that duty and pleaded that it was not responsible for the development of the method of shoring the excavation.[29] SJ Weir contended at trial that it was not negligent because it was merely following the instructions of the engineer Meinhardt and in the alternative it was only liable for a proportionate share of its responsibility as between SJ Weir and Meinhardt pursuant to s 72 of the Development Act 1993 (SA) (“the Act”).
[29] Defence [37] and [39].
The trial Judge summarised the parties’ respective cases as follows:
[7]…Construction of the ramp required extensive excavation along that boundary which, in turn, required a temporary retaining structure to prevent movement of soil under the Bijoks’ property and possible damage to the buildings and driveway. The builder constructed a retaining wall which proved inadequate and soil escaped from the Bijoks’ property, causing subsidence, especially under their carport, and damage to the carport, driveway and house.
[8] The plaintiffs’ case is that the builder, to save money, used a retaining structure which was not approved by the engineers and was inadequate.
[9] The builder’s case is that it is faultless, that the engineers provided a design upon which it acted. It is not the builder’s fault that the structure was inadequate.
[10]The engineer has never been a party to the action. Mr Vreugdenburg denies that Meinhardt ever approved, for use along the carport section of the boundary, the retaining wall which the builder used.
[11] The chief factual issue for me to decide is this: did Meinhardt approve the wall built to retain the carport?

The trial Judge, accepting Mr Vreugdenburg’s evidence, went on at [34] to reject SJ Weir’s case that Meinhardt had ever created or communicated to SJ Weir a design of a temporary retaining wall involving columns at 1150mm centres without propping adjacent to the carport (as opposed to adjacent to the driveway). This conclusion is challenged by SJ Weir on appeal (“ground 2”).
The trial Judge found at [34] that there was no further escape of sand after 4 August 2003 and inferred from this fact that SJ Weir on or prior to 2 August 2003 caused the subsidence on that date. This conclusion is challenged by SJ Weir on appeal (“ground 3”).
The trial Judge at [38] rejected the contention by SJ Weir that its liability to the Bijoks (if established) was limited by s 72 of the Act to a proportionate share given SJ Weir’s allegation that the subsidence was also caused by the negligence of Meinhardt. This conclusion is challenged by SJ Weir on appeal (“ground 4”).
Accordingly, the trial Judge found SJ Weir liable in negligence for all of the damage caused to the Bijoks’ carport, driveway and retaining wall as a result of the subsidence.
Nuisance
SJ Weir does not challenge the trial Judge’s conclusion that it was the occupier of the development site for the purposes of the law of nuisance and thereby liable for any nuisance created by the excavation.
SJ Weir does not challenge the trial Judge’s conclusion that the Bijoks as land owners had a right to support of their land in its natural state by adjoining land. Nor do the Bijoks challenge the trial Judge’s conclusion that the Bijoks did not have a right of support for the carport per se.
The challenge by SJ Weir to the trial Judge’s conclusion is that the trial Judge ought to have found that the subsidence was caused by the additional weight of the Bijoks’ carport on the land and hence no nuisance was committed.
General legal principles
The following general principles have been established in relation to the right of support by adjoining land and the tort of nuisance in respect of the removal of such support.
1.“An owner of land has a right to the support of that land in its natural state from the adjacent and subjacent land of neighbouring owners.”[30]
2.“This right is a natural incident of the ownership” of the land itself.[31]
3.An interference by an adjoining land owner with the right of support only occurs, and the tort of nuisance is only committed, at the point at which the owner’s land subsides, as opposed to the point at which the adjoining land owner excavates or take away the support.[32]
4.“There is no natural right of support for structures (as distinct from the natural right of support for land in its natural state).”[33]
5.A right of support for structures can be acquired by the grant of an easement, or at common law (subject to the Real Property Act) by prescription through the structure having relied upon such support uninterrupted for at least 20 years.[34]
6.Such a right of support of structures is in the nature of an easement, as opposed to a natural incident of the land itself, and is governed for example by the Prescription Act 1832 (UK).[35]
7.Once a right of support of structures has been acquired, its incidents are the same as the right of support of natural land.[36]
8.“Damages for injury to a structure flowing from subsidence caused by a withdrawal of support (as distinct from the additional weight of structures on the land) are recoverable.”[37]
9.Conversely, if the support is withdrawn and the land would not have subsided but for the weight of the structures thereon, there is no interference with the right of support of the land.[38]
[30] Jemena Gas Networks (NSW) Ltd v Mine Subsidence Board (2011) 85 ALJR 666; [2011] HCA 19 at [32] per French CJ, Gummow, Hayne, Hayden, Crennan and Kiefel JJ citing Dalton v Henry Angus & Co (1881) 6 App Cas 740 at 791 per Lord Selborne, 808-809 per Lord Blackburn (Lord Coleridge agreeing).
[31] Jemena Gas Networks (NSW) Ltd v Mine Subsidence Board (2011) 85 ALJR 666; [2011] HCA 19 at [32] per French CJ, Gummow, Hayne, Hayden, Crennan and Kiefel JJ citing Dalton v Henry Angus & Co (1881) 6 App Cas 740 at 791 per Lord Selborne, 808-809 per Lord Blackburn (Lord Coleridge agreeing).
[32] Bonomi v Backhouse (1859) EB & E 646; Backhouse v Bonomoi (1861) 9 HL Cas 503 at 512 per Lord Westbury; Dalton v Henry Angus & Co (1881) 6 App Cas 740 at 791 per Lord Selborne, 808-809 per Lord Blackburn (Lord Coleridge agreeing); Darley Main Colliery Ltd v Mitchell (1886) 11 AC 127 at 133 per Lord Halsbury.
[33] Jemena Gas Networks (NSW) Ltd v Mine Subsidence Board [2011] HCA 19 at [32] per French CJ, Gummow, Hayne, Hayden, Crennan and Kiefel JJ citing Dalton v Henry Angus & Co (1881) 6 App Cas 740 at 791-792 per Lord Selborne, 803-804 per Lord Penzance, 809-810 per Lord Blackburn, 830 per Lord Watson (Lord Coleridge agreeing).
[34] Dalton v Henry Angus & Co (1881) 6 App Cas 740 at 791-792 per Lord Selborne, 803-804 per Lord Penzance, 809-810 per Lord Blackburn, 830 per Lord Watson (Lord Coleridge agreeing); Bognuda v Upton & Shearer Ltd [1972] NZLR 741 at 757 per North P, 760-761 per Turner J, 767-769 per Woodhouse J; Walker v Adelaide City Corporation (2004) 88 SASR 225 at [261] per Perry J; Kebewar Pty Ltd v Harkin (1987) 9 NSWLR 738 at 740-741 per McHugh JA (Samuals JA and Priestley JA agreeing); Morgan v Lake Macquarie City Council [1993] NSWCA 184 (Unreported, NSW Court of Appeal, 2 September 1993) at 6 per Clarke JA (Handley JA and Cripps JA agreeing).
[35] Dalton v Henry Angus & Co (1881) 6 App Cas 740 at 791-792 per Lord Selborne, 803-804 per Lord Penzance, 809-810 per Lord Blackburn, 830 per Lord Watson (Lord Coleridge agreeing); Bognuda v Upton & Shearer Ltd [1972] NZLR 741 at 757 per North P, 760-761 per Turner J, 767-769 per Woodhouse J; Walker v Adelaide City Corporation (2004) 88 SASR 225 at [261] per Perry J; Kebewar Pty Ltd v Harkin (1987) 9 NSWLR 738 at 740-741 per McHugh JA (Samuals JA and Priestley JA agreeing); Morgan v Lake Macquarie City Council [1993] NSWCA 184 (Unreported, NSW Court of Appeal, 2 September 1993) at 6 per Clarke JA (Handley JA and Cripps JA agreeing).
[36] Dalton v Henry Angus & Co (1881) 6 App Cas 740 at 791-792 per Lord Selborne, 803-804 per Lord Penzance, 809-810 per Lord Blackburn, 830 per Lord Watson (Lord Coleridge agreeing); Bognuda v Upton & Shearer Ltd [1972] NZLR 741 at 757 per North P, 760-761 per Turner J, 767-769 per Woodhouse J.
[37] Jemena Gas Networks (NSW) Ltd v Mine Subsidence Board [2011] HCA 19 at [32] per French CJ, Gummow, Hayne, Hayden, Crennan and Kiefel JJ citing Brown v Robins (1859) 4 H & N 186 (157 ER 809) and Dalton v Henry Angus & Co (1881) 6 App Cas 740 at 791-792 per Lord Selborne, 803-804 per Lord Penzance, 809-810 per Lord Blackburn, 830 per Lord Watson (Lord Coleridge agreeing).
[38] Dalton v Henry Angus & Co (1881) 6 App Cas 740 at 791-792 per Lord Selborne, 803-804 per Lord Penzance, 809-810 per Lord Blackburn, 830 per Lord Watson (Lord Coleridge agreeing); Bognuda v Upton & Shearer Ltd [1972] NZLR 741 at 757 per North P, 760-761 per Turner J, 767-769 per Woodhouse J; Walker v Adelaide City Corporation (2004) 88 SASR 225 at [261] per Perry J.
Application to facts
In the present case, the only evidence concerning causation of the subsidence was given by the expert witness Mr Kokkinakis. The relevant evidence in cross-examination was as follows:
"QI want you to assume that the calculated of force of the weight of the building above was 5.4 kiloNewtons at the area of the carport. Would the consequence of that application of force to the foundation soils, that is the sand, mean that that sand at that point was more likely to be subject to subsidence if the lateral support was removed.
ANo, not more likely to subsidence but a greater degree of subsidence.
QSo the propensity for the sand to move would exist whatever the load.
AYes.
QBut the extent of the subsidence would be magnified by the weight that’s being applied by the building.
AYes.
In re-examination, Mr Kokkinakis gave the following evidence:
QKnowing what you know about the method that was adopted by the builder and the temporary shoring that was used, would the subsidence have occurred if the building was not there.
AYes.
Mr Kokkinakis’ evidence clearly established that the subsidence would have occurred if the carport has not been there, but it also established that the subsidence was more extensive because the carport was there than it would otherwise have been. Neither party explored at trial the extent to which the degree of the subsidence was increased due to the weight of the carport.
In these circumstances, the issue arises upon which party does the onus of proof lie to establish the extent to which the structure was damaged as a result of a more extensive subsidence due to the force exerted by the structure itself.
Once it was established that there would have been some subsidence and hence some damage to the buildings even if the additional weight of the buildings had not been present, the question arises whether an onus then fell upon SJ Weir to establish the extent to which the damage was increased (if at all) due to the force of the buildings themselves on the soil.
It is a general principle that, at least in certain circumstances, once a plaintiff proves that the defendant’s wrongful conduct is a cause of injury to the plaintiff, the onus shifts to the defendant to prove that the injury was in fact caused or was exacerbated by a different cause.[39]
[39] Middleton v Melbourne Tramway & Omnibus Co Ltd (1913) 16 CLR 572 at 580-581 per Barton ACJ, 590 per Isaacs J (Rich J agreeing); Savini v Australian Terrazzo and Concrete Co Pty Ltd [1959] VR 811 at 812-813 per Herring CJ and Gavan Duffy J, 820-821 per Sholl J; Parkes v Crittenden (1965) 114 CLR 164 at 167-168 per Barwick CJ, Kitto and Taylor JJ, 170-171 per Windeyer J; Terry v Leventeris [2011] SASCFC 26 at [28] per Gray J (Sulan J and Vanstone J agreeing).
For example, in Middleton v Melbourne Tramway and Omnibus Co Ltd,[40] a boy was injured by a tram which failed to stop sufficiently quickly after hitting him. The case proceeded on the basis that, without negligence by the tram driver, the tram still would have proceeded in pushing the boy some 48 feet, but due to negligence the tram took some 67 feet to stop, being an additional 19 feet. The High Court held that the onus was on the Tramway Company to prove the extent to which the boy would have suffered injuries if the tram had stopped within 48 feet. Barton ACJ held:
[40] (1913) 16 CLR 572.
The defendant company…contended that it was for the plaintiff to show the specific damage applicable to that part of their conduct which is found to have been negligent…But that it is not the plaintiff’s duty, but the defendants’, to show facts involving an apportionment of the damage is, I think, apparent from the case of Nitro‑Phosphate and Odam’s Chemical Manure Co v London and St Katherine Docks Co.[41]
Isaac J held:
But, where the evidence for the plaintiff, if believed, is sufficient not only to establish liability, but also to enable a jury with reasonable certainly, if they so conclude, to attribute to the defendant’s wrongful conduct as an effective and proximate cause the injuries complained of, the plaintiff has so far discharged his burden of proof… The onus is then on the defendant… to negative the inference of his total responsibility, or to distribute the damage arising by showing, if he can, that the damage accrued, or must in any case have accrued, wholly or partly from some other cause.[42]
In Savini v Australian Terrazzo and Concrete Co Pty Ltd,[43] Sholl J held:
Now I think one may start with the proposition, which may be accepted as axiomatic, that the plaintiff bears the ultimate onus… of proving his loss… but if a plaintiff proves damage which prima facie flows from a tort committed against him by a defendant he will, if no more appears, recover for it. And if the defendant alleges that some of the plaintiff’s loss is actually due to a cause or causes other than the tort it is not enough for him to show that some damage of that kind may be included in the plaintiff’s loss; it must show how it can be quantified and severed.[44]
In Watts v Rake,[45] Dixon CJ held:
But for the defendant it is answered… second, that a part of his present condition is traceable to causes other than the accident, and thirdly, that had there been no accident he would eventually and prematurely have been incapacitated by the seeds of disability within him… as to the second and third of these answers, there is undoubtedly a presumptio hominis in the plaintiff’s favour which any tribunal of fact should insist that the defendant should overcome. If the disabilities of the plaintiff can be disentangled and one or more traced to causes in which the injuries he sustained though the accident played no part, it is the defendant who should be required to do the disentangling and to exclude the operation of the accident as a contributory cause.[46]
[41] (1913) 16 CLR 572 at 580-581.
[42] (1913) 16 CLR 572 at 590.
[43] [1959] VLR 811.
[44] [1959] VLR 811 at 820-821.
[45] (1960) 108 CLR 158.
[46] (1960) 108 CLR 158 at 160.
In the present case, the force exerted by the natural land was substantial in itself, being in the vicinity of 17 kiloNewtons, whereas the force exerted by the building was in the vicinity of 5 kiloNewtons. Given Mr Kokkinakis’ evidence that the subsidence would still have occurred even without the additional weight of the buildings, it is likely that substantial cracking and damage to the carport and driveway would still have occurred even without the additional weight of those structures. In these circumstances, it was incumbent upon SJ Weir to adduce evidence permitting the identification of the degree (if at all) to which the loss and damage was increased by the supervening weight of the building.
As SJ Weir adduced no such evidence, Mr and Mrs Bijok were entitled to recover the full amount of their loss and damage caused by the subsidence.
I reject the first ground of appeal.
Negligence cause of action
Negligence
SJ Weir argues on appeal that the trial Judge erred in finding that Meinhardt never created or communicated to SJ Weir a design of a temporary retaining wall at 1150mm centres without propping upon which SJ Weir relied or could have relied.
SJ Weir’s contention is based upon evidence by Mr Weir. Mr Weir gave evidence that, at the meeting on 23 June 2003, he requested Meinhardt to consider amending their design of the temporary retaining wall to “open up the centres”, meaning to increase the spacing between the steel columns from 1150mm to 1500mm to save cost. Mr Weir implied that Meinhardt only included props as part of the design when they increased the spacing to 1500mm, and that the earlier design involving unpropped 1150mm spacings applied to the area adjacent to the carport as well as the driveway. Mr Weir said or implied that a Meinhardt engineer, Mr Lee, had informed an SJ Weir employee, Mr Thiele, on a date not identified that the design for the steel columns adjacent to the driveway could simply be transposed and applied to the boundary adjacent to the carport. Neither Mr Thiele nor Mr Lee gave evidence at trial.
SJ Weir has demonstrated no error in the approach or findings of the trial Judge. To the extent that the trial Judge’s findings rely upon his assessment of the credibility of the witnesses, there is no basis for SJ Weir to challenge it. To the extent it relies on the objective evidence, the trial Judge was correct in rejecting SJ Weir’s contention for the following reasons.
1.Mr Weir in his evidence did not identify any occasion on which he himself was informed (either orally or in writing) by Meinhardt that it was appropriate to use unpropped steel columns at 1150mm spacings adjacent to the carport. SJ Weir did not call Mr Thiele, and did not adduce any admissible evidence that Meinhardt ever created, authorised or communicated such a design.
2.Meinhardt prepared designs for the temporary retaining wall on 12-13 June and again in the first half of July 2003, they prepared detailed computerised and handwritten drawings and computations. By contrast, there were no drawings, computations or other documents whatsoever created by Meinhardt in relation to the design alleged by SJ Weir for unpropped columns at 1150mm spacings adjacent to the carport.
3.The contemporaneous documents prepared by Meinhardt in June and July 2003 clearly showed the design for propped columns at 1500mm centres as being an alternative to underpinning, as opposed to an alternative to unpropped 1150 centres. In this regard, Mr Vreugdenburg’s handwritten notes of the meeting of 23 June at Item 5 contain a simple drawing of the steel columns with the designation “Prop top” appearing under the heading “Underpinning detail to be reviewed”. Similarly, the computations and drawings of early July 2003 are entitled “Underpinning Alternatives”. This is inconsistent with Mr Weir’s evidence that the discussion on 23 June was about “opening up” the centres.
4.Mr Vreugdenburg in cross-examination denied that Meinhardt ever contemplated a design involving unpropped steel columns adjacent to the Bijoks’ carport. He explained that the reason he increased the spacing of the steel columns adjacent to the carport (compared to adjacent to the driveway) was that, once the steel columns were propped (the first conclusion), they did not need to be so closely spaced (the second conclusion). He denied that the evolution occurred the other way around. The objective evidence corroborated this account.
5.SJ Weir received drawings and computations from Meinhardt in respect of the other designs. It is almost inconceivable that SJ Weir acted on a purely verbal statement from the engineer in respect of the alleged alternative design for the temporary retaining wall adjacent to the carport.
6.The letter by SJ Weir to the Bijoks dated 13 June 2003 shows that SJ Weir had unilaterally extended the temporary retaining wall design to the boundary adjacent to the carport without any reference to Meinhardt.
I reject the second ground of appeal.
Causation
SJ Weir argues contends that the trial Judge erred in concluding that the negligence of SJ Weir was the cause of the escape of sand (and hence of the subsidence and consequential damage to the carport, driveway and retaining wall).
SJ Weir’s contention is that there was no evidence and the Bijoks did not prove at trial that the failure by SJ Weir to prop the steel columns caused the escape of sand from the Bijok’s land into the development land.
The trial Judge at [34] inferred from the fact that there was no subsequent incident involving the escape of sand from the Bijok land into the development land after or in the nature of the incident which occurred on 2 August 2003 that the escape which occurred on 2 August 2003 was caused by the negligence of SJ Weir.
To the extent that the trial Judge is to be understood as inferring that it was the installation of props after 2 August 2003 which prevented a subsequent escape of sand or as finding that the failure to prop was a cause of the escape of sand on 2 August 2003, I accept that there is some force in SJ Weir’s contention.
However, the Bijok’s case as pleaded and as analysed by the trial Judge and referred to at [26] to [28] above was not such a narrow case. The Bijok’s case was that the excavation and installation of the temporary retaining wall by SJ Weir caused the escape of sand and that SJ Weir did not take adequate care to prevent that from occurring. This was a classic res ipsa loquitur case. As found by the trial Judge, Mr Weir was familiar with dune sand and hence must have been aware of the need for great care to be exercised when excavating it. Crucially, SJ Weir’s workers covered up the escape of sand shortly after it occurred on 2 August 2003, before Mr Bijok or the engineers could witness its nature or location. The Bijoks necessarily were in a position where they could not identify the precise cause of the escape of sand. SJ Weir chose not to call its workers to identify how or where the escape occurred. The circumstances were such that an escape would not ordinarily occur in the absence of the exercise of reasonable care generally in the excavation and installation of the temporary retaining wall. In these circumstances, I agree with Gray and Sulan JJ that res ipsa loquitur principles apply.

On that premise, it follows that, if negligence is established in this way, causation of loss by that negligence is simultaneously established. The trial Judge did not need to rely upon the fact that there was no subsequent escape of sand to infer either negligence or causation. However, that circumstance was an additional circumstance fortifying a conclusion of negligence (and hence causation) in the first place.
Accordingly, I would uphold the trial Judge’s conclusion on the issue of causation, but for somewhat differing reasons.
I reject the third ground of appeal.
Proportionate liability
SJ Weir contends that the trial Judge erred in rejecting SJ Weir’s contention that its liability was limited to a proportionate share on the basis that Meinhardt was also negligent in its design of the temporary retaining wall.
In order to secure a proportionate reduction in its own liability pursuant to s 72 of the Act, SJ Weir was obliged to prove both that Meinhardt was negligent in its design of the temporary retaining wall and that such negligence was a cause of the escape of sand and consequential subsidence and damage.
SJ Weir did not call any expert or other evidence of its own to prove negligence by Meinhardt. Rather, it relied upon 2 reports by Mr Kokkinakis tendered by the Bijoks as part of their case against SJ Weir. SJ Weir also cross‑examined Mr Vreugdenburg, but he denied negligence.
The trial Judge at [38] found that Mr Kokkinakis did not express an opinion that the Meinhardt design (which incorporated propping) was defective or negligent and hence SJ Weir failed to establish negligence of Meinhardt for the purposes of s 72 of the Act.
There is some force in SJ Weir’s contention on appeal that Mr Kokkinakis’ reports were capable of being read as applying to both propped and unpropped columns.
However, in his reports, Mr Kokkinakis said that he personally considered the method of shoring as inappropriate for the particular site. He went on to express the opinion that the settlement of the sands was “a direct result of the inadequate precautions taken during construction in the adjacent property and in particular the works undertaken directly adjacent to the eastern boundary.” Mr Kokkinakis did not state that in his opinion no competent engineer would have stipulated the method of shoring stipulated by Meinhardt or otherwise express an opinion that Meinhardt was negligent in its stipulation of the method of shoring. Mr Kokkinakis was not asked this question in cross‑examination by SJ Weir. In these circumstances, SJ Weir failed to establish that Meinhardt was negligent.
In any event, it is clear that SJ Weir did not establish that any negligence by Meinhardt caused the escape of sand. To prove causation, it was incumbent on SJ Weir to call its workers to prove the nature, precise location and mechanism of the escape of sand and in particular to prove that it was not caused solely by SJ Weir’s negligence. This SJ Weir failed to do.
Accordingly, SJ Weir failed to demonstrate that the negligence of Meinhardt was a cause of the subsidence and thereby failed to invoke s 72 of Development Act.
I reject the fourth ground of appeal.
Conclusion
I would dismiss the appeal.